GPS技术在西贾庄-罗集铁矿项目中的应用     

韩昱  项立斌  余涛  江冬明 《安徽地质》2014,(2):131-133

全球定位系统GPS(GlobalPositimingSystem),以其连续、实时、高精度、全天候测量和自动化程度高等优点,对经典大地测量学的诸多方面产生了极其深刻的影响,在与物化探测量相关的控制测量及测网布设中的应用也越来越广泛。该文通过一个物探项目中GPS测量整体方案的设计与实践过程,针对GPS控制测量、RTK测量、手持GPS测量几种作业方法的探讨及对相关数据的分析,概括总结了GPS技术应用于地勘项目的若干特点。  相似文献   

雅鲁藏布江结合带东段仁布-曲松地层分区上三叠统朗杰学(岩)群层序及构造样式再认识          下载免费PDF全文

张占武  张文峰  曾庆高  韩湘涛 《沉积与特提斯地质》2014,(1):72-80

雅鲁藏布江结合带东段夹在南、北两条蛇绿混杂岩带之间的一套活动类型的上三叠统朗杰学(岩)群,许多地质工作者对其地层层序、沉积特征、变形变质、物质来源以及形成的构造环境进行过研究。作者在前人工作成果的基础上,综合对比了已往区调工作获得的实际资料,以(构造)岩石地层为基础,结合沉积古生物特征、变形特征以及区域大地构造背景,对该岩(群)作了进一步的研究。初步认为:朗杰学(岩)群地层层序自老至新为宋热(岩)组、江雄(岩)组和姐德秀(岩)组(章村岩组);郎杰学(岩)群的构造样式为一"Ω"型两翼不对称的复式背斜构造。  相似文献   

内蒙古东乌旗达勒廷查干矿区成矿特征及成因类型浅析     

胡卫星  韩晓平  朱金海  马维  李开 《地质与资源》2014,23(Z1)

内蒙古东乌旗达勒廷查干矿区位于宝格达山西南约70km处,是近两年以地、物、化、工程综合方法新发现的铅锌银多金属矿产地.矿区地处西伯利亚板块东南缘,考虑到其所处成矿环境,研究其成矿特征及成因类型,不论是对于矿区本身后续阶段的勘查,还是对邻区的矿产勘查以及成矿区带的研究均具有借鉴意义.  相似文献   

Spatial heterogeneity of cyanobacteria-inoculated sand dunes significantly influences artificial biological soil crusts in the Hopq Desert (China)   总被引：2，自引：1，他引：1  

Hua Li  Benqiang Rao  Gaohong Wang  Si Shen  Dunhai Li  Chunxiang Hu  Yongding Liu 《Environmental Earth Sciences》2014,71(1):245-253

Artificial biological soil crusts (ABSCs), formed by inoculating Microcoleus vaginatus Gom. and Scytonema javanicum Born. et Flah. onto the topsoil of desert dunes, proved to be effective tools for the stabilization of moving dunes and promotion of soil fertility. As dominant driving forces in arid habitats, the abiotic environmental conditions of undulating dunes produce a gradient of abiotic stresses on cyanobacteria. Cyanobacteria are considered pioneering phototrophs in early soil crust communities in deserts. In this study, the development of ABSCs under various environmental site conditions was investigated using 16S rRNA-based polymerase chain reaction, denaturing gradient gel electrophoresis (DGGE), and soil property measurements. After inoculation in 2002 and long-term development, patchy moss crusts were observed on the dunes. All of the available sequenced bands in the DGGE gels belonged to Oscillatoriales and Nostocales. The dominant Nostocales genus in the ABSCs was still Scytonema; however, more Oscillatoriales genera were identified, which belonged to Microcoleus and Phormidium. The cyanobacterial compositions of different slope types were significantly distinct (p < 0.05), particularly those from windward slopes. The crusts of the top-dune slopes were more heterogeneous. In addition, the soil physicochemical properties and richness indices of the windward slopes were significantly lower than those of the leeward and interdune slopes (p < 0.05). Compared with uninoculated control dunes, all of the inoculated dunes had far higher biodiversities.  相似文献   

Decoupling of the East Asian summer monsoon and Indian summer monsoon between 20 and 17 ka   总被引：2，自引：0，他引：2  

Xiuyang Jiang  Yaoqi He  Chuan-Chou Shen  Shi-Yu Lee  Bang Yang  Ke Lin  Zhizhong Li 《Quaternary Research》2014

Marine Oxygen Isotope Stage (MIS) 2, with its profound environmental and climatic changes from before the last glacial maximum (LGM) to the last deglaciation, is an ideal period for understanding the evolution of the East Asian summer monsoon (EASM) and Indian summer monsoon (ISM), two Asian monsoon sub-systems. With 875 stable oxygen isotope ratios and 43 ²³⁰Th dates from stalagmites in Sanxing Cave, southwestern China, we construct and interpret a new, replicated, Asian summer monsoon (ASM) record covering 30.9–9.7 ka with decadal resolution. δ¹⁸O records from this site and other reported Chinese caves display similar long-term orbitally dominated trends and synchronous millennial-scale strong and weak monsoonal events associated with climate changes in high northern latitudes. Interestingly, Sanxing δ¹⁸O and Arabian Sea records show a weakening ISM from 22 to 17 ka, while the Hulu and Qingtian records from East and Central China express a 3-ka intensifying EASM from 20 to 17 ka. This decoupling between EASM and ISM may be due to different sensitivities of the two ASM sub-systems in response to internal feedback mechanisms associated with the complex geographical or land-ocean configurations.  相似文献   

青海西部尕斯库勒盐湖沉积物中铀和钍地球化学特征探讨     

叶传永  王志明  郝伟林  林效宾  韩军  郑绵平 《矿床地质》2014,33(5):1081-1090

文章以柴达木盆地西部尕斯库勒盐湖沉积物为研究对象,通过对钻孔沉积物和地表沉积物中铀和钍含量的研究,探讨了盐湖沉积物中铀和钍的地球化学特征。分析表明,钻孔沉积物中铀和钍之间存在明显的正相关关系。在横向上,随地表取样点逐渐远离湖表卤水,沉积物中铀和钍的含量先增高后又急剧降低,且受补给水铀含量影响大;在纵向上,同一个晶间卤水层或者碎屑物沉积层内铀含量垂直分异明显,铀含量随深度增加而递增。就沉积物中铀和钍的赋存形式而言,2/3的铀被黏土质点吸附,1/3的铀夹杂在盐类矿物中;而90%以上的钍被黏土质点吸附,10%以下的钍夹杂在盐类矿物中。干盐滩中毛细蒸发和淋滤等化学沉积分异作用造成盐湖沉积中心的沉积物铀含量相对较高。  相似文献   

皖赣两省地质公园造景花岗岩的岩石特征、形成时代及景观成因     

李鹏举  李红英  韩亚超  邱骏挺  余心起 《地质论评》2014,60(6):1348-1358

皖赣两省气候宜人,旅游资源丰富。黄山、三清山、天柱山、九华山、牯牛降等地质公园更是以独特的花岗岩地貌景观闻名于世。通过对地质公园内造景花岗岩进行年代学、岩石学、地球化学等方面的研究,证明上述地质公园内的花岗岩集中形成于135~125 Ma,属于早白垩世强烈岩浆活动的产物。这些花岗岩高硅、富碱、过铝,轻重稀土分馏不明显,Eu强烈亏损,稀土配分曲线呈海鸥型;强烈亏损Ba、Sr、P、Ti,形成四个明显的凹槽,具有造山后铝质A型花岗岩的岩石地化特征,属于铝质A型花岗岩或者高分异花岗岩。上述花岗岩主要形成于造山后伸展的构造背景。该构造背景下产出的花岗岩以浅色矿物为主,暗色矿物含量稀少,抗风化蚀变能力更佳;并具有多组密集的原生节理,对花岗岩地貌景观的形成起着极其重要的控制作用。  相似文献   

新疆西天山智博铁矿岩浆-热液成矿作用—来自安山岩矿物学的证据     

沈立军 《地质与勘探》2014,50(2):321-331

本文以智博铁矿区内的安山岩为研究对象,通过详细的野外地质调查,并利用电子显微镜和电子探针,对安山岩中的主要矿物进行了系统的岩相学观察和矿物学研究。研究表明,智博安山岩中斜长石主要为Na-高钠长石,具低TiO2,高Na2O和Al2O3的特点;辉石主要为普通辉石,具高TiO2,高Al2O3的特点;角闪石主要为镁角闪石和阳起石,具低TiO2和Al2O3,高MgO的特点;副矿物磁铁矿具高TiO2,低MgO和Al2O3的特点。辉石、角闪石矿物化学特征表明,智博铁矿安山岩的母岩浆属于壳幔混源的玄武质岩浆,构造环境为火山岛弧环境。智博安山岩中单斜辉石结晶温度为1225℃左右,结晶压力约0.795GPa,结晶深度约26km。智博铁矿后期的热液作用也参与了磁铁矿成矿,对智博铁矿的成矿有一定的贡献。  相似文献   

Time-Varying Multifractal Characteristics and Formation Mechanism of Loaded Coal Electromagnetic Radiation     

Shaobin Hu  Enyuan Wang  Zhonghui Li  Rongxi Shen  Jie Liu 《Rock Mechanics and Rock Engineering》2014,47(5):1821-1838

Dynamic collapses of deeply mined coal rocks are severe threats to miners. To predict the collapses more accurately using electromagnetic radiation (EMR), we investigate the time-varying multifractal characteristics and formation mechanism of EMR induced by underground coal mining. A series of uniaxial compression and multi-stage loading experiments with coal samples of different mechanical properties were carried out. The EMR signals during their damage evolution were monitored in real-time; the inherent law of EMR time series was analyzed by fractal theory. The results show that the time-varying multifractal characteristics of EMR are determined by damage evolutions process, the dissipated energy caused by damage evolutions such as crack propagation, fractal sliding and shearing can be regard as the fingerprint of various EMR micro-mechanics. Based on the Irreversible thermodynamics and damage mechanics, we introduced the damage internal variable, constructed the dissipative potential function and established the coupled model of the EMR and the dissipative energy, which revealed the nature of dynamic nonlinear characteristics of EMR. Dynamic multifractal spectrum is the objective response of EMR signals, thus it can be used to evaluate the coal deformation and fracture process.  相似文献   

Coal Mine Roadway Stability in Soft Rock: A Case Study     

Baotang Shen 《Rock Mechanics and Rock Engineering》2014,47(6):2225-2238

Roadway instability has always been a major concern in deep underground coal mines where the surrounding rock strata and coal seams are weak and the in situ stresses are high. Under the high overburden and tectonic stresses, roadways could collapse or experience excessive deformation, which not only endangers mining personnel but could also reduce the functionality of the roadway and halt production. This paper describes a case study on the stability of roadways in an underground coal mine in Shanxi Province, China. The mine was using a longwall method to extract coal at a depth of approximately 350 m. Both the coal seam and surrounding rock strata were extremely weak and vulnerable to weathering. Large roadway deformation and severe roadway instabilities had been experienced in the past, hence, an investigation of the roadway failure mechanism and new support designs were needed. This study started with an in situ stress measurement programme to determine the stress orientation and magnitude in the mine. It was found that the major horizontal stress was more than twice the vertical stress in the East–West direction, perpendicular to the gateroads of the longwall panel. The high horizontal stresses and low strength of coal and surrounding rock strata were the main causes of roadway instabilities. Detailed numerical modeling was conducted to evaluate the roadway stability and deformation under different roof support scenarios. Based on the modeling results, a new roadway support design was proposed, which included an optimal cable/bolt arrangement, full length grouting, and high pre-tensioning of bolts and cables. It was expected the new design could reduce the roadway deformation by 50 %. A field experiment using the new support design was carried out by the mine in a 100 m long roadway section. Detailed extensometry and stress monitorings were conducted in the experimental roadway section as well as sections using the old support design. The experimental section produced a much better roadway profile than the previous roadway sections. The monitoring data indicated that the roadway deformation in the experimental section was at least 40–50 % less than the previous sections. This case study demonstrated that through careful investigation and optimal support design, roadway stability in soft rock conditions can be significantly improved.  相似文献